base64.c

/*************************************************************************** * base64.c -- Base64 encoding. * ***********************IMPORTANT NMAP LICENSE TERMS************************ * * * The Nmap Security Scanner is (C) 1996-2009 Insecure.Com LLC. Nmap is * * also a registered trademark of Insecure.Com LLC. This program is free * * software; you may redistribute and/or modify it under the terms of the * * GNU General Public License as published by the Free Software * * Foundation; Version 2 with the clarifications and exceptions described * * below. This guarantees your right to use, modify, and redistribute * * this software under certain conditions. If you wish to embed Nmap * * technology into proprietary software, we sell alternative licenses * * (contact sales@insecure.com). Dozens of software vendors already * * license Nmap technology such as host discovery, port scanning, OS * * detection, and version detection. * * * * Note that the GPL places important restrictions on "derived works", yet * * it does not provide a detailed definition of that term. To avoid * * misunderstandings, we consider an application to constitute a * * "derivative work" for the purpose of this license if it does any of the * * following: * * o Integrates source code from Nmap * * o Reads or includes Nmap copyrighted data files, such as * * nmap-os-db or nmap-service-probes. * * o Executes Nmap and parses the results (as opposed to typical shell or * * execution-menu apps, which simply display raw Nmap output and so are * * not derivative works.) * * o Integrates/includes/aggregates Nmap into a proprietary executable * * installer, such as those produced by InstallShield. * * o Links to a library or executes a program that does any of the above * * * * The term "Nmap" should be taken to also include any portions or derived * * works of Nmap. This list is not exclusive, but is meant to clarify our * * interpretation of derived works with some common examples. Our * * interpretation applies only to Nmap--we don't speak for other people's * * GPL works. * * * * If you have any questions about the GPL licensing restrictions on using * * Nmap in non-GPL works, we would be happy to help. As mentioned above, * * we also offer alternative license to integrate Nmap into proprietary * * applications and appliances. These contracts have been sold to dozens * * of software vendors, and generally include a perpetual license as well * * as providing for priority support and updates as well as helping to * * fund the continued development of Nmap technology. Please email * * sales@insecure.com for further information. * * * * As a special exception to the GPL terms, Insecure.Com LLC grants * * permission to link the code of this program with any version of the * * OpenSSL library which is distributed under a license identical to that * * listed in the included COPYING.OpenSSL file, and distribute linked * * combinations including the two. You must obey the GNU GPL in all * * respects for all of the code used other than OpenSSL. If you modify * * this file, you may extend this exception to your version of the file, * * but you are not obligated to do so. * * * * If you received these files with a written license agreement or * * contract stating terms other than the terms above, then that * * alternative license agreement takes precedence over these comments. * * * * Source is provided to this software because we believe users have a * * right to know exactly what a program is going to do before they run it. * * This also allows you to audit the software for security holes (none * * have been found so far). * * * * Source code also allows you to port Nmap to new platforms, fix bugs, * * and add new features. You are highly encouraged to send your changes * * to nmap-dev@insecure.org for possible incorporation into the main * * distribution. By sending these changes to Fyodor or one of the * * Insecure.Org development mailing lists, it is assumed that you are * * offering the Nmap Project (Insecure.Com LLC) the unlimited, * * non-exclusive right to reuse, modify, and relicense the code. Nmap * * will always be available Open Source, but this is important because the * * inability to relicense code has caused devastating problems for other * * Free Software projects (such as KDE and NASM). We also occasionally * * relicense the code to third parties as discussed above. If you wish to * * specify special license conditions of your contributions, just say so * * when you send them. * * * * This program is distributed in the hope that it will be useful, but * * WITHOUT ANY WARRANTY; without even the implied warranty of * * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * * General Public License v2.0 for more details at * * http://www.gnu.org/licenses/gpl-2.0.html , or in the COPYING file * * included with Nmap. * * * ***************************************************************************//* $Id$ */#include "base64.h"#include "nbase.h"staticint b64enc_internal(constunsignedchar *data, int len, char *dest)
{
/* base64 alphabet, taken from rfc3548 */char *b64alpha = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
char *buf = dest;
/* Encode three bytes per iteration ala rfc3548. */while (len >= 3) {
buf[0] = b64alpha[(data[0] >> 2) & 0x3f];
buf[1] = b64alpha[((data[0] << 4) & 0x30) | ((data[1] >> 4) & 0xf)];
buf[2] = b64alpha[((data[1] << 2) & 0x3c) | ((data[2] >> 6) & 0x3)];
buf[3] = b64alpha[data[2] & 0x3f];
data += 3;
buf += 4;
len -= 3;
}
/* Pad the remaining bytes. len is 0, 1, or 2 here. */if (len > 0) {
buf[0] = b64alpha[(data[0] >> 2) & 0x3f];
if (len > 1) {
buf[1] = b64alpha[((data[0] << 4) & 0x30) | ((data[1] >> 4) & 0xf)];
buf[2] = b64alpha[(data[1] << 2) & 0x3c];
} else {
buf[1] = b64alpha[(data[0] << 4) & 0x30];
buf[2] = '=';
}
buf[3] = '=';
buf += 4;
}
/* * As mentioned in rfc3548, we need to be careful about * how we null terminate and handle embedded null-termination. */
*buf = '\0';
return (buf - dest);
}
/* Take in plain text and encode into base64. */char *b64enc(constunsignedchar *data, int len)
{
char *dest;
/* malloc enough space to do something useful */
dest = (char*)safe_malloc(4 * len / 3 + 4);
dest[0] = '\0';
/* Call internal function to base64 encode data */
b64enc_internal(data, len, dest);
return (dest);
}